Isoprene-ethylene copolymer

Alternating isoprene-ethylene copolymers (IER) were prepared with the same catalyst. Due to the strictly alternating sequences of diene and olefin units and the absence of chiral carbon atoms IER shows strain-induced crystallization, but at lower temperatures compared to natural rubber. 

The copolymers consist of strictly alternating sequences of diene and olefin. C-NMR measurements Showed the microstructure of the butadiene units in BPR to be exclusively of the trans-1,4 configuration (Figure 8). The isoprene units in isoprene-ethylene copolymer (IER) contain 84 % trans-1,4, 15 % cis-1,4, and 1 % 3,4 structures (Figure 9). Spontaneous crystallization in unstretched BPR samples was detected by dilatometry and confirmed by X-ray diffraction and DSC measurements. The extrapolated equilibrium melting point is about -10 °C. 

Polyolefin Polyester Block copolymers of styrene and butadiene or styrene and isoprene Block copolymers of styrene and ethylene or styrene and butylene Poly(vinyl chloride) and poly(vinyl acetate) ... 

The effect of blending LDPE with EVA or a styrene-isoprene block copolymer was investigated (178). The properties (thermal expansion coefficient. Young s modulus, thermal conductivity) of the foamed blends usually lie between the limits of the foamed constituents, although the relationship between property and blend content is not always linear. The reasons must he in the microstructure most polymer pairs are immiscible, but some such as PS/polyphenylene oxide (PPO) are miscible. Eor the immiscible blends, the majority phase tends to be continuous, but the form of the minor phase can vary. Blends of EVA and metallocene catalysed ethylene-octene copolymer have different morphologies depending on the EVA content (5). With 25% EVA, the EVA phase appears as fine spherical inclusions in the LDPE matrix. The results of these experiments on polymer films will apply to foams made from the same polymers. 

Styrene-butadiene block copolymer Styrene-isoprene block copolymer Styrene-ethylene block copolymer Styrene-butylene block copolymer... 

Random copolymers of butadiene, isoprene and/or pentadiene with ethylene and/or propylene have been obtained in the presence of various catalysts, mainly based on Ti or V compounds [206,207]. Statistical butadiene/ethylene copolymers can also be formed with zirconocene catalysts [162]. 

S-DMS refers to styrene-dimethylsiloxane diblock copolymers S-l refers to sty-rene-isoprene diblock copolymers S-l-S and I-S-I refer to styrene-isoprene-styrene and to isoprene-styrene-isoprene triblock copolymers, respectively and S-EO and EO-S-EO refer to styrene-ethylene oxide diblock copolymers and to ethylene oxide-styrene-ethylene oxide triblock copolymers, respectively. 

High density polyethylene (HOPE) Linear low density polyethylene (LLDPE) Isotactic polypropylene (iPP) Syndiotactic polypropylene (sPP) tram-1,4-Polyisoprene Syndiotactic polystyrene (sPS) Cyclooleflns Ethylene-propylene copolymers Styrene-ethylene copolymers cw -1,4-polybutadiene rrarw -1,4-Poly isoprene Random ethylene-a-olefin copolymers Ethylene-propylene rubber (EPR) Ethylene-propylene-diene copolymers (EPDM)... 

Produced by a solution polymerization process, this material exhibited an ordered molecular structure with the styrene monomer located at the ends of the butadiene monomer chain. In addition, other monomers such as isoprene, ethylene, butylene, and others, could be added to the polymer chain, which further modified basic properties. These materials possess a continuous rubber phase for resilience and toughness, and a discontinuous plastic phase for solubility and thermoplasticity. A variety of different grades are also available for this type of SBR, with differences in molecular weight, differences in the types of monomers used, differences in structural configuration, and differences in the ratio of endblock to midblock. Both emulsion and solution polymerized grades of SBR are available as solvent-based and water-based adhesives and sealants. Block copolymers are extensively used for hot melt formulations and both water-based and solvent-based pressure sensitive adhesive applications. Today, SBR elastomers are the most popular elastomers used for the manufacture of adhesives and sealants. 

G. Floudas, B. Vazaiou, F. Schipper, R. Ulrich, U. Wiesner, H. latrou and N. Hadjichristidis, Poly(ethylene oxide-b-isoprene) Diblock Copolymer Phase Diagram, Macromolecules 34 2947 (2001). 

The category of elastomers includes a wide range of products, such as natural rubber (NR), styrene-butadiene rubber (SBR), styrene-butadiene-styrene copolymer (SBS known as thermoplastic rubber), styrene-isoprene-styrene copolymer (SIS), polyurethane rubber, polyether-polyester copolymer, olefinic copolymers, ethylene-propylene rubber (EPR) and so on (see also Table 3.16). 

Semicrystalline ethylene-propylene copolymer, EP, was blended with amorphous EP and inorganic filler. The blends had good processability, mechanical properties, and impact strength. In the Mitsubishi patent, crystalline EP was blended with styrene-isoprene block copolymer, 5-30 wt% SIS, and polystyrene, 3-5 wt% PS, to give good paintability... 

Pressure-sensitive adhesive dispersions are based primarily on special acrylic ester copolymers, again generally in combination with resins. In addition to suitable resins, two polymer bases are used primarily for hot-melt pressure-sensitive adhesives, namely, ethylene-vinyl-acetate copolymers and styrene-butadiene or styrene-isoprene block copolymers, which also are known as thermoplastic rubbers. 

LLDPE -I- NR was compatibilized by adding ethylene-b-isoprene diblock copolymer, as judged by mechanical properties [196]. 

Some specific recent applications of the GC-MS technique to various types of polymers include the following PE [49,50], poly(l-octene) [51], poly(l-decene) [51], poly(l-dodecene) [51], 1-octene-l-decene-l-dodecene terpolymer [51], chlorinated polyethylene [52], polyolefins [53, 54], acrylic acid methacrylic acid copolymers [55], polyacrylates [56], styrene-butadiene and other rubbers [57-59], nitrile rubber [60], natural rubbers [61, 62], chlorinated natural rubber [63, 64], polychloroprene [65], PVC [66-68], silicones [69, 70], polycarbonates [71], styrene-isoprene copolymers [72], substituted PS [73], polypropylene carbonate [74], ethylene-vinyl acetate copolymers [75], Nylon [76], polyisopropenyl cyclohexane a-methyl styrene copolymers [77], m-cresol-novolac epoxy resins [78], polymeric flame retardants [79], poly(4-N-alkyl styrenes) [80], polyvinyl pyrrolidone [81], vinyl pyrrolidone-methyl acryloxysilicone copolymers [82], polybutylcyanoacrylate [83], polysulfide copolymers [84], poly(diethyl-2-methacryloxy)ethyl phosphate [85], ethane-carbon monoxide copolymers [86], polyetherimide [87], bisphenol A [88], ethyl styrene [89], styrene-isoprene block copolymer [89], polyvinyl alcohol-co-vinyl acetate [90], epoxide thiol [91], maleic acid-propylene copolymer [92], P-hydroxy butyrate-P-hydroxy valerate copolymer [93], polycaprolactams [39,94], PS [95,96], polypyrrole [95,96], polyhydroxy alkanoates [97], poly(p-chloromethyl) styrene [81], polybenzooxazines and siloxy substituted polyoxadisila-pentanylenes [98,99] poly benzyl methacrylates [100], polyolefin blends after ageing in soil [101] and polystyrene peroxide [43]. 

C150H186 hexabenzocoronene derivative polymantanes acenaphthofluoranthenes c/s-polyisoprene -[CH2C(CH3)=CHCH2].-isoprene—isobutylene copolymer styrene—butadiene copolymer ethylene—propylene copolymer liquid crystal (component for photovoltaic films) new material hydrocarbons built from fused adamantine units conductive ladder polymer natural rubber synthetic rubber... 

Styrene-Butadiene-Styrene Block Copolymers. Styrene blocks associate into domains that form hard regions. The midblock, which is normally butadiene, ethylene-butene, or isoprene blocks, forms the soft domains. Polystyrene domains serve as cross-links. 

Commercially, anionic polymerization is limited to three monomers styrene, butadiene, and isoprene [78-79-5], therefore only two useful A—B—A block copolymers, S—B—S and S—I—S, can be produced direcdy. In both cases, the elastomer segments contain double bonds which are reactive and limit the stabhity of the product. To improve stabhity, the polybutadiene mid-segment can be polymerized as a random mixture of two stmctural forms, the 1,4 and 1,2 isomers, by addition of an inert polar material to the polymerization solvent ethers and amines have been suggested for this purpose (46). Upon hydrogenation, these isomers give a copolymer of ethylene and butylene. 

Thermoplastic block copolymers were used for pressure-sensitive and hot-melt rubber adhesives as from the middle sixties. These adhesives found application in packaging, disposable diapers, labels and tapes, among other industrial markets. The formulation of these adhesives generally includes an elastomer (generally containing styrene endblocks and either isoprene, butadiene or ethylene-butylene midblocks) and a tackifier (mainly a rosin derivative or hydrocarbon resin). 

Currently, important TPE s include blends of semicrystalline thermoplastic polyolefins such as propylene copolymers, with ethylene-propylene terepolymer elastomer. Block copolymers of styrene with other monomers such as butadiene, isoprene, and ethylene or ethylene/propy-lene are the most widely used TPE s. Styrene-butadiene-styrene (SBS) accounted for 70% of global styrene block copolymers (SBC). Currently, global capacity of SBC is approximately 1.1 million tons. Polyurethane thermoplastic elastomers are relatively more expensive then other TPE s. However, they are noted for their flexibility, strength, toughness, and abrasion and chemical resistance. Blends of polyvinyl chloride with elastomers such as butyl are widely used in Japan. ... 

Standard butyl rubber, which is a copolymer of isobutylene with about 2% of isoprene vulcanises in the same manner as natural rubber but, as it only contains a small proportion of polyisoprene, the cross-link percentage is much reduced. It is therefore not possible to make ebonite from a butyl rubber. The same vulcanisation chemistry, with some modifications, applies to ethylene-propylene terpolymers and brominated butyl rubber. 

The isoprene units in the copolymer impart the ability to crosslink the product. Polystyrene is far too rigid to be used as an elastomer but styrene copolymers with 1,3-butadiene (SBR rubber) are quite flexible and rubbery. Polyethylene is a crystalline plastic while ethylene-propylene copolymers and terpolymers of ethylene, propylene and diene (e.g., dicyclopentadiene, hexa-1,4-diene, 2-ethylidenenorborn-5-ene) are elastomers (EPR and EPDM rubbers). Nitrile or NBR rubber is a copolymer of acrylonitrile and 1,3-butadiene. Vinylidene fluoride-chlorotrifluoroethylene and olefin-acrylic ester copolymers and 1,3-butadiene-styrene-vinyl pyridine terpolymer are examples of specialty elastomers. 

Other commercial copolymers which are typically random are those of vinyl chloride and vinyl acetate (Vinylite), isobutylene and isoprene (butyl rubber), styrene and butadiene (SBR), and acrylonitrile and butadiene (NBR). The accepted nomenclature is illustrated by EP, which is designated poly-ethylene-co-propylene the co designating that the polymer is a copolymer. When the copolymers are arranged in a regular sequence in the chains, i.e., ABAB, the copolymer is called an alternating copolymer. A copolymer consisting of styrene and maleic anhydride (SMA) is a typical alternating copolymer. 

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